Mobile terminal having antenna

ABSTRACT

A mobile terminal that can prevent radiation performance deterioration of an antenna is provided. The mobile terminal includes a circuit board in which an antenna and one or more key buttons are mounted, a housing mounted on the antenna and the circuit board, and a case for enclosing a periphery of the one or more key buttons and having a plurality of openings according to the quantity of the key buttons, wherein an antenna adjacent opening among the plurality of openings is extended through a slot toward an edge of the case to embody a loop antenna. Therefore, radiation deterioration of an antenna due to a case can be prevented. In addition, production costs can be minimized, and a desired external appearance of the mobile terminal is not compromised.

PRIORITY

This application claims the benefit under 35 U.S.C. §119(a) of a Koreanpatent application filed on Sep. 23, 2011 in the Korean IntellectualProperty Office and assigned Serial No. 10-2011-0096203, the entiredisclosure of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention:

The present invention relates to a mobile terminal having an antenna.More particularly, the present invention relates to a mobile terminalthat can prevent radiation performance deterioration of an antenna.

2. Description of the Related Art:

In order to reduce the thickness of a mobile terminal, to reinforce thestrength thereof, and to improve the appearance of the mobile terminal,the outside of the mobile terminal is typically made of metal.Consequently, since using metal deteriorates the radiation performanceof an antenna, in order to prevent radiation performance deteriorationof the antenna, various design methods are applied.

A first design method is a method of separating a metal forming theoutside of the mobile terminal from the antenna. According to such adesign method, an injection material is used instead of metal at a lowerend of the mobile terminal at which the antenna is positioned. However,a limitation exists in improving the appearance of the mobile terminaland in reinforcing the strength thereof

A second design method is a method of forming a slot in a metal plate,such as a metal battery cover forming the outside of the mobileterminal. In such a design method, because a position, length, width,and shape of a slot corresponding to a specific frequency should bedetermined in a wide metal plate, such as the metal battery cover,extensive tuning must be performed. Further, due to such a slot, anexternal appearance of the mobile terminal is much deformed from aninitially desired shape in view of a design.

A third design method is a method of connecting a metal forming theoutside of the mobile terminal and a ground pad of an antenna. Accordingto such a design method, because a connection part for connecting themetal and the ground pad of the antenna is added and a welding processof welding the connection part to the metal is added, production costsincreases. In addition, as the connection part and a welding layer dueto the welding process are added, a thickness of the mobile terminalincreases.

Therefore, a need exists for a mobile terminal that can preventradiation performance deterioration of an antenna due to an element madeof metal forming the outside of the mobile terminal

SUMMARY OF THE INVENTION

Aspects of the present invention are to address at least theabove-mentioned problems and/or disadvantages and to provide at leastthe advantages described below. Accordingly, an aspect of the presentinvention is to provide a mobile terminal that can prevent radiationperformance deterioration of an antenna due to an element made of metalforming the outside of the mobile terminal

Another aspect of the present invention is to provide a mobile terminalthat can minimize production cost and deformation of a design accordingto coupling of constituent elements when preventing radiationperformance deterioration of an antenna.

In accordance with an aspect of the present invention, a mobile terminalis provided. The mobile terminal includes a circuit board for mounting amain antenna, for processing a signal to be radiated, and for outputtingthe signal to the main antenna, and a housing, mounted on the mainantenna and the circuit board, for embodying a loop antenna having astructure for passing through a circumferential area of at least one ofkey buttons in order to radiate, when a signal radiated from the mainantenna is output, the output signal.

In accordance with another aspect of the present invention, a mobileterminal is provided. The mobile terminal comprises a circuit board inwhich an antenna and one or more key buttons are mounted, a housingmounted on the antenna and the circuit board, and a case for enclosing aperiphery of the one or more key buttons and having a plurality ofopenings according to the quantity of the one or more key buttons,wherein an antenna adjacent opening among the plurality of openings isextended through a slot toward the edge of the case to embody a loopantenna.

Other aspects, advantages, and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is an exploded perspective view illustrating a mobile terminalaccording to an exemplary embodiment of the present invention;

FIG. 2 is a coupled perspective view illustrating a mobile terminalaccording to an exemplary embodiment of the present invention.

FIG. 3 is a partial cross-sectional view of the mobile terminal of FIG.2 taken along line A-A′ according to an exemplary embodiment of thepresent invention;

FIG. 4 is a diagram illustrating a simulation result of a case accordingto Comparative Example;

FIG. 5 is a diagram illustrating a simulation result of a case accordingto an exemplary embodiment of the present invention;

FIG. 6 is a graph illustrating reflection loss of an antenna of a mobileterminal according to Comparative Example;

FIG. 7 is a graph illustrating reflection loss of an antenna of a mobileterminal according to an exemplary embodiment of the present invention;

FIG. 8 is a graph illustrating a Voltage Standing Wave Ratio (VSWR) ofan antenna of a mobile terminal according to Comparative Example;

FIG. 9 is a graph illustrating a VSWR of an antenna of a mobile terminalaccording to an exemplary embodiment of the present invention;

FIG. 10 is a perspective view illustrating a mobile terminal accordingto an exemplary embodiment of the present invention;

FIG. 11 is a partial cross-sectional view illustrating the mobileterminal of FIG. 10 taken along line J-J′ according to an exemplaryembodiment of the present invention; and

FIG. 12 is a perspective view illustrating a mobile terminal accordingto an exemplary embodiment of the present invention.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features, andstructures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of exemplaryembodiments of the invention as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the embodiments described hereincan be made without departing from the scope and spirit of theinvention. In addition, descriptions of well-known functions andconstructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are notlimited to the bibliographical meanings, but, are merely used by theinventor to enable a clear and consistent understanding of theinvention. Accordingly, it should be apparent to those skilled in theart that the following description of exemplary embodiments of thepresent invention is provided for illustration purpose only and not forthe purpose of limiting the invention as defined by the appended claimsand their equivalents.

It is to be understood that the singular forms “a,” “an,” and “the”include plural referents unless the context clearly dictates otherwise.Thus, for example, reference to “a component surface” includes referenceto one or more of such surfaces.

By the term “substantially” it is meant that the recited characteristic,parameter, or value need not be achieved exactly, but that deviations orvariations, including for example, tolerances, measurement error,measurement accuracy limitations and other factors known to those ofskill in the art, may occur in amounts that do not preclude the effectthe characteristic was intended to provide.

FIGS. 1 through 12, discussed below, and the various exemplaryembodiments used to describe the principles of the present disclosure inthis patent document are by way of illustration only and should not beconstrued in any way that would limit the scope of the disclosure. Thoseskilled in the art will understand that the principles of the presentdisclosure may be implemented in any suitably arranged communicationssystem. The terms used to describe various embodiments are exemplary. Itshould be understood that these are provided to merely aid theunderstanding of the description, and that their use and definitions inno way limit the scope of the invention. Terms first, second, and thelike are used to differentiate between objects having the sameterminology and are in no way intended to represent a chronologicalorder, unless where explicitly stated otherwise. A set is defined as anon-empty set including at least one element.

FIG. 1 is an exploded perspective view illustrating a mobile terminalaccording to an exemplary embodiment of the present invention, FIG. 2 isa coupled perspective view illustrating a mobile terminal according toan exemplary embodiment of the present invention, and FIG. 3 is apartial cross-sectional view of the mobile terminal of FIG. 2 takenalong line A-A′ according to an exemplary embodiment of the presentinvention. For reference, key buttons 171 and 172 are shown in FIGS. 2and 3, but for convenience of description, key buttons 171 and 172 arenot shown in FIG. 1.

Referring to FIGS. 1 through 3, a mobile terminal 100 includes anantenna 110, a circuit board 120, a display unit 138, a microphone (notshown), a case 140, a housing 153, a battery cover 160, key buttons 171and 172, and a battery 180.

The antenna 110 radiates a signal in a resonant frequency band and ismounted at one surface of the circuit board 120. In the presentexemplary embodiment, the antenna 110 may be referred to as a mainantenna and may be mounted in a rear surface 120 b of the circuit board120, as shown in FIG. 3. The antenna 110 is a carrier antenna includinga carrier 111 and an antenna pattern 112 formed in the carrier 111.However, the antenna 110 is not limited thereto and may be a PrintedCircuit Board (PCB) antenna in which an antenna pattern is formed in thecircuit board 120.

The key buttons 171 and 172 are means for inputting information, such asa phone number or a character, and are mounted in a front surface 120 aof the circuit board 120. The key button 172 includes a dome terminal121, a conductive dome 122, a substrate terminal 123, and a buttonportion 173. The conductive dome 122 is disposed at a lower part of thebutton portion 173, and the dome terminal 121 connected to acircumferential edge of the conductive dome 122 and the substrateterminal 123 disposed at the inside of the dome terminal 121 are formedat the front surface 120 a of the circuit board 120. When a user pressesthe button portion 173, the conductive dome 122 and the substrateterminal 123 contact, and the dome terminal 121 and the substrateterminal 123 are electrically connected through the conductive dome 122.Accordingly, an electrical signal corresponding to a user input occursin the key button 172.

The circuit substrate 120 mounts components, such as the antenna 110,the key buttons 171 and 172, and the microphone, and includes acontroller (not shown) for processing a signal to be radiated from theantenna 110.

The display unit 138 displays an image to a user and includes a display137 and a window 145. The display 137 is disposed at an upper part ofthe circuit board 120. The display 137 may be a Liquid Crystal Display(LCD) or an Active Matrix Organic Light Emitting Diode (AMOLED) and isconnected to the circuit board 120 through a Flexible Printed CircuitBoard (FPCB) (not shown). The window 145 is disposed at an upper part ofthe display 137, transmits an image of the display 137 to a user, andprotects the display 137. The window 145 may be made of glass,PolyCarbonate (PC) or PolyEthylene Terephthalate (PET).

The microphone converts a user's voice to an electrical signal andoutputs the electrical signal to the controller of the circuit board120. In the present exemplary embodiment, the microphone is not shown inthe drawings, but may be mounted in the front surface 120 a of thecircuit board 120.

The housing 153 includes a front housing 130 for housing the front sideof the circuit board 120 and a rear housing 150 for housing the rearside of the circuit board 120. The front housing 130 and the rearhousing 150 are made of an insulating material. The front housing 130 isdisposed on the circuit board 120. The front housing 130 includesopenings 131 for positioning the key buttons 171, a display space 134for positioning the display 137, a receiver hole 135, and a microphonehole 191, as shown in FIGS. 1 and 2. A receiver (not shown) foroutputting another party's voice to a user of the mobile terminal 100 ispositioned within the receiver hole 135. The microphone hole 191 outputsa user's voice to the microphone and is formed in a lower end portion ofthe front housing 130. One end of the microphone hole 191 of the fronthousing 130 is connected to a microphone mounted in the circuit board120, and the other end thereof is connected to a microphone hole 190 ofthe case 140. The rear housing 150 includes an antenna space 151 forpositioning the antenna 110 and a battery space 152 for positioning thebattery 180.

The case 140 forms the outside of the mobile terminal 100 and is mountedin the front housing 130. The case 140 is made of metal. The case 140includes a plurality of openings 141 and 142 for passing through andexposing each of the key buttons 171 and 172, window space 144 forpositioning the window 145, and the microphone hole 190. The pluralityof openings 141 and 142 are arranged in a lattice structure in the case140. Accordingly, in a portion forming the plurality of openings 141 inthe case 140, metal portions of a plurality of character shapes ‘-’orthogonally intersect each other and thus have a lattice shape whenviewing from the front side of the mobile terminal 100.

An antenna adjacent opening 142 adjacent to the antenna 110 among theplurality of openings 171 and 172 is extended toward the edge of thecase 140 through a slot 143. In the present exemplary embodiment, theslot 143 is extended to the edge of the case 140. The case 140 forms aloop structure L in a peripheral area of the slot 143 and the antennaadjacent opening 142.

Electromagnetic waves radiated from the antenna 110 are induced to apair of opposite metal portions 145 a and 145 b with the slot 143interposed there between, and different electronic potentials occur inthe pair of metal portions 145 a and 145 b. For example, it is assumedthat an electric potential of the left metal portion 145 a of the slot143 is lower than that of the right metal portion 145 b of the slot 143.In such a case, a current generated in the left metal portion 145 a ofthe slot 143 flows along a peripheral area of the antenna adjacentopening 142 and arrives at the right metal portion 145 b of the slot143. Accordingly, in the case 140, as current flows along the loopstructure L formed by a peripheral area of the slot 143 and the antennaadjacent opening 142, a loop antenna is embodied in the case 140.Accordingly, the case 140 radiates a signal output from the antenna 110.

In the present exemplary embodiment, the case 140 is a separate elementthat is not included in the housing 153. However, the housing 153 mayinclude the case 140 as well as the front housing 130 and the rearhousing 150. In such a case, a signal radiated from the main antenna 110is output to the housing 153, and the housing 153 embodies a loopantenna while radiating again the output signal.

The battery 180 supplies power to the mobile terminal 100 and isdisposed within the battery space 152 of the rear housing 150, as shownin FIG. 3. The battery cover 160 covers to protect the battery 180 fromthe outside and is mounted at the rear side of the rear housing 150 andthe battery 180.

FIG. 4 is a diagram illustrating a simulation result of a case accordingto Comparative Example, and FIG. 5 is a diagram illustrating asimulation result of a case according to an exemplary embodiment of thepresent invention. For reference, a case 340 according to ComparativeExample is different from the case 140 in that the slot 143 is notformed, but the remaining configurations of the case 340 according toComparative Example are the same as those of the case 140.

Patterns E, F, G, H, and I shown in FIGS. 4 and 5 represent intensity ofa current flow and define declining intensities of a current flow inorder of a solid line pattern E, a gravel pattern F, a crossing patternof solid and dotted lines G, a grass pattern H, and a point pattern I.That is, pattern E represents the strongest current flow.

Referring to FIG. 4, a portion adjacent to an antenna pattern 312 in thecase 340 does not have a slot but has a continued form. A portionforming a plurality of openings 341 in the case 340 has a lattice shape.Accordingly, electromagnetic waves radiated from the antenna pattern 312are output to the case 340, and a current is removed while repeatedlycirculating along a metal portion having a lattice shape. Therefore, asshown in FIG. 5, a metal portion adjacent to an antenna pattern as wellas a metal portion having a lattice shape does not represent a strongcurrent flow.

Referring to FIG. 5, the antenna adjacent opening 142 adjacent to theantenna pattern 112 among a plurality of openings 141 and 142 of thecase 140 is extended to the edge of the case 140 through the slot 143.Accordingly, in the case 140 shown in FIG. 5, even if a metal portionforming the plurality of openings 141 and 142 has a lattice shape, as inthe case 340 shown in FIG. 4, a current flow of a peripheral area of theslot 143 and the antenna adjacent opening 142 and a periphery thereof isvery strong, as represented by a solid line pattern E.

FIG. 6 is a graph illustrating reflection loss of an antenna of a mobileterminal according to Comparative Example, FIG. 7 is a graphillustrating reflection loss of an antenna of a mobile terminalaccording to an exemplary embodiment of the present invention, FIG. 8 isa graph illustrating a Voltage Standing Wave Ratio (VSWR) of an antennaof a mobile terminal according to Comparative Example, and FIG. 9 is agraph illustrating a VSWR of an antenna of a mobile terminal accordingto an exemplary embodiment of the present invention. For reference,FIGS. 6 through 9 represent actual measured results, a mobile terminal(not shown) according to Comparative Example measured in FIGS. 6 and 8is different from the mobile terminal 100 in that the slot 143 is notformed, but the remaining configurations of the mobile terminal (notshown) according to Comparative Example measured in FIGS. 6 and 8 arethe same as those of the mobile terminal 100.

Referring to FIG. 6, the mobile terminal according to ComparativeExample represents a peak of reflection loss of −20 dB in a highfrequency band of 1.71 GHz to 1.99 GHz. However, referring to FIG. 7,the mobile terminal 100 represents a peak of reflection loss of −30 dBin a high frequency band of 1.71 GHz to 1.99 GHz. That is, the mobileterminal 100 has lower reflection loss in a higher frequency band thanComparative Example.

Referring to FIG. 8, the mobile terminal according to ComparativeExample represents parasitic resonance D in a peak C of a VSWR in a highfrequency band. However, referring to FIG. 9, the mobile terminal 100does not represent parasitic resonance in a peak B of a VSWR in a highfrequency band. That is, the mobile terminal 100 has a stabilized VSWRin a higher frequency band than Comparative Example.

Table 1 represents radiation efficiency of an antenna of the mobileterminal according to Comparative Example measured in FIGS. 6 and 8, andTable 2 represents radiation efficiency of an antenna of the mobileterminal measured in FIGS. 7 and 9.

TABLE 1 Frequency Radiation Average (MHz) efficiency (%) (%) 824 9 16.10837 10 849 12 869 18 881 21 894 26 880 19 29.13 896 27 912 30 928 33 94433 960 32 1710 6 14.22 1745 9 1785 12 1805 14 1840 18 1880 26 1850 2714.68 1880 16 1910 13 1930 10 1960 11 1990 10

TABLE 2 Frequency Radiation Average (MHz) efficiency (%) (%) 824 7 15.81837 10 849 12 869 18 881 21 894 27 880 21 32.33 896 28 912 33 928 37 94438 960 37 1710 19 24.73 1745 30 1785 29 1805 28 1840 26 1880 16 1850 1920.59 1880 26 1910 23 1930 24 1960 16 1990 15

Referring to Tables 1 and 2, the mobile terminal 100 has the sameradiation efficiency as that of Comparative Example in a low frequencyband of 824 MHz to 960 MHz and has radiation efficiency higher by 6 to10% than that of Comparative Example in a high frequency band of 1710MHz to 1990 MHz.

Table 3 represents receiving sensitivity and transmitting power of anantenna of a mobile terminal according to Comparative Example and theexemplary embodiment of the present invention measured in FIGS. 6through 9. For reference, Global System for Mobile communications 850(GSM850) has a frequency band of 824 MHz to 894 MHz, Extended GSM (EGSM)has a frequency band of 880 MHz to 960 MHz, Digital Communication System(DCS) has a frequency band of 1710 MHz to 1880 MHz, and PersonalCommunication System (PCS) has a frequency band of 1850 MHz to 1990 MHz.Furthermore, the unit of a numerical value described in Table 2 is dBm,and the ‘difference’ described in Table 3 is a value in which an averageof Comparative Example is subtracted from an average of the exemplaryembodiment of the present invention.

TABLE 3 Frequency Comparative Example First exemplary embodiment bandChannel Low Middle High Average Low Middle High Average DifferenceGSM850 Sensitivity −102.27 −102.65 −104.65 −103.19 −102.06 −102.81−104.58 −103.15 0.04 Power 15.77 21.04 24.69 20.50 16.06 21.61 24.8420.84 0.33 EGS-M Sensitivity −105.47 −104.85 −104.73 −105.02 −105.81−105.22 −105.86 −105.30 −0.28 Power 27.66 27.81 28.23 27.90 27.61 27.6228.21 27.81 −0.08 DCS Sensitivity −105.89 −105.47 −105.78 −105.71−104.54 −103.74 −102.99 −103.76 1.96 Power 23.18 23.78 24.75 23.90 25.9225.92 25.53 25.79 1.89 PCS Sensitivity −104.74 −104.12 −102.90 −103.92−100.27 −99.36 −99.03 −99.55 4.37 Power 22.83 22.48 22.38 22.56 24.7225.33 26.11 25.39 2.82

Referring to Table 3, the mobile terminal 100 has the same receivingsensitivity and transmitting power as those of Comparative Example in alow frequency band of 824 MHz to 960 MHz and has receiving sensitivityand transmitting power higher by about 2 dBms to 4 dBms than ComparativeExample in a high frequency band of 1710 MHz to 1990 MHz.

FIG. 10 is a perspective view illustrating a mobile terminal accordingto an exemplary embodiment of the present invention, and FIG. 11 is apartial cross-sectional view of the mobile terminal of FIG. 10 takenalong line J-J′ according to an exemplary embodiment of the presentinvention.

Referring to FIGS. 10 and 11, a mobile terminal 200 includes an antenna210, a circuit board 220, a display unit 238, a case 240, a housing 253,a battery cover 260, key buttons 271 and 272, a battery 280, and amicrophone 292.

The antenna 210, the circuit board 220, the display unit 238, thebattery cover 260, the key buttons 271 and 272, and the battery 280 havethe same configuration as that of the exemplary embodiment of FIG. 2.That is, the antenna 210 includes a carrier 211 and an antenna pattern212 formed in the carrier 211 and is mounted in the circuit board 220,and the key buttons 271 and 272 include a button portion 273, aconductive dome 222, a substrate terminal 223, and a dome terminal 221and is mounted in the circuit board 220, and the circuit board 220includes a controller (not shown) for processing a signal to be radiatedfrom the antenna 210.

In an exemplary implementation, the microphone 292 is mounted in aportion adjacent to a slot 243 of a front surface of the circuit board220, as shown in FIG. 11. Furthermore, a soundproof member 293 forpreventing noise of the inside of the mobile terminal from being outputto the microphone 292 may be attached to the outside of the microphone292.

The case 240 has an insulating portion 291 forming a microphone hole 290at the inside of the slot 243, unlike the case 140 of the exemplaryembodiment of FIG. 2. The microphone hole 290 is connected to themicrophone 292 mounted in the circuit board 220. The microphone hole 290is formed by connecting a hole 290 a formed by the insulating portion291 and a hole 290 b formed in a front housing 230. The insulatingportion 291 includes a first insulating portion 291 a and a secondinsulating portion 291 b. In this case, as the first insulating portion291 a and the second insulating portion 291 b are separated from eachother in the slot 243, the microphone hole 290 is formed between thefirst insulating portion 291 a and the second insulating portion 291 b.The insulating portion 291 is formed by attaching a plastic piece to thefront housing 230. In this case, by applying paints of the same color asthat of the case 240 at a surface of the insulating portion 291, theappearance of the mobile terminal can be improved.

The housing 253 includes the front housing 230 and a rear housing 250and has the same configuration as that of the housing 153 of theexemplary embodiment of FIG. 2 except that a hole 290 b forming themicrophone hole 290 is formed adjacent to the slot 243 in the fronthousing 230.

According to an exemplary implementation, the insulating portion 291forming the microphone hole 290 is inserted into the slot 243.Accordingly, appearance deterioration of the mobile terminal 200 can beprevented by a portion exposed through the slot 243 in the front housing230. Furthermore, because the insulating portion 291 does not have aconductive property, different electric potentials occur in a pair ofopposite metal portions with the slot 243 interposed therebetween withthe same method as that of the exemplary embodiment of FIG. 2.Accordingly, as current flows along a loop structure L′ in a peripheralarea of the slot 243 and the antenna adjacent opening 242 in the case240, a loop antenna is embodied.

FIG. 12 is a perspective view illustrating a mobile terminal accordingto an exemplary embodiment of the present invention.

Referring to FIG. 12, a mobile terminal 400 includes a display unit 438,a housing 453, key buttons 471 and 472, and a case 440, wherein anantenna adjacent opening 442 extended to the edge through a slot 443 isextended to an opening 444 of the remaining openings through anotherslot 445 (hereinafter, an ‘additional slot’). The housing 453 includesthe front housing 430 and a rear housing 450 and has the sameconfiguration as that of the housing 153 of the exemplary embodiment ofFIG. 2 Accordingly, in the case 440, a loop structure L″ formed by aperipheral area of each of the slot 443, the antenna adjacent opening442, the additional slot 445, and the opening 444 connected to theantenna adjacent opening 442 through the additional slot 445 is formedlonger than the loop L shown in FIG. 2. Therefore, a loop antennaembodied by the case 440 of this exemplary embodiment has a lengthlonger than a loop antenna embodied by the case 140 of the exemplaryembodiment of FIG. 2 and thus can radiate an antenna signal having alower resonant frequency.

In FIG. 12, the additional slot 445 is extended to only one opening 444of the remaining openings, however an additional slot may be extended toa plurality of openings of the remaining openings. For example, anadditional slot may be connected to an opening of a key button ‘*’ andan opening of a key button ‘#’ as well as an opening 444 of a key button‘8’ 473.

According to an exemplary embodiment of the present invention, anantenna adjacent opening among a plurality of openings formed in a caseis extended toward the edge of the case through a slot. Accordingly,electromagnetic waves radiated from the antenna are induced to aperipheral area of a slot in the case, and current of a loop shape flowsthrough a peripheral area of the slot and the antenna adjacent openingin the case, and thus a loop antenna can be embodied in the case.Therefore, in a mobile terminal, radiation performance deterioration ofan antenna due to a case can be prevented.

Because only a slot is formed in the case without connecting the caseand a ground pad of the antenna, a separate material or manufacturingprocess is not added thereby preventing unnecessary production cost.Furthermore, because an opening for a key button of the case has astructure extended to an edge portion of the case through the slot, anexternal appearance of the mobile terminal can be prevented from beingdeformed from an initially desired shape in view of a design.

While the invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A mobile terminal comprising: a circuit board formounting a main antenna, for processing a signal to be radiated, and foroutputting the signal to the main antenna; and a housing, mounted on themain antenna and the circuit board, for embodying a loop antenna havinga structure for passing through a circumferential area of at least oneof key buttons in order to radiate, when a signal radiated from the mainantenna is output, the output signal.
 2. The mobile terminal of claim 1,wherein the housing comprises: a front housing disposed on the circuitboard and in which a plurality of key buttons are disposed; and a casedisposed at an upper part of the front housing in order to cover thefront housing and in which the loop antenna is embodied.
 3. The mobileterminal of claim 2, wherein the case has a structure in which aplurality of openings for exposing the plurality of key buttons areformed.
 4. The mobile terminal of claim 3, wherein the loop antenna isembodied as an opening adjacent to the main antenna among the openingsand is extended toward an edge of the case through a slot.
 5. The mobileterminal of claim 2, wherein the case has a lattice shape.
 6. The mobileterminal of claim 4, wherein the opening extended through the slot isfurther extended in another opening direction through another slot. 7.The mobile terminal of claim 2, wherein the case comprises a metal case.8. A mobile terminal comprising: a circuit board in which an antenna andone or more key buttons are mounted; a housing mounted on the antennaand the circuit board; and a case for enclosing a periphery of the oneor more key buttons and having a plurality of openings according to thequantity of the key buttons, wherein an antenna adjacent opening amongthe plurality of openings is extended through a slot toward an edge ofthe case to embody a loop antenna.
 9. The mobile terminal of claim 8,wherein the case comprises a metal case.
 10. The mobile terminal ofclaim 8, wherein the case has a lattice shape by a portion forming aplurality of openings.
 11. The mobile terminal of claim 8, wherein theslot is formed from the antenna adjacent opening to the edge of thecase.
 12. The mobile terminal of claim 8, wherein a portion forming theslot in the case forms a loop with a portion forming the antennaadjacent opening of the case.
 13. The mobile terminal of claim 8,wherein the slot has an insulating portion forming a microphone holetherein.
 14. The mobile terminal of claim 13, wherein the microphonehole exposes a microphone mounted in the circuit board.
 15. The mobileterminal of claim 8, wherein the antenna adjacent opening is furtherextended in a direction of any opening of the plurality of openingsthrough another slot.